Teses em Biotecnologia (Doutorado) - PPGBIOTEC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/7377
O Doutorado em Biotecnologia teve início em 2011 e funciona no Programa de Pós-Graduação em Biotecnologia (PPGBIOTEC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) O uso de compostos fenólicos na prevenção da doença de parkinson: análise bibliométrica e crítica dos 100 artigos mais citados da Web of Science e avaliação neuroprotetora do açaí (euterpe oleracea) em ratos wistar(Universidade Federal do Pará, 2022-12) SANTOS JUNIOR, José Messias dos; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468; HTTPS://ORCID.ORG/0000-0003-1486-4013; ROGEZ, Hervé Louis Ghislain; http://lattes.cnpq.br/5202118426597590; https://orcid.org/0000-0001-8925-8881Parkinson's disease is characterized by the death of dopaminergic neurons with both motor and non-motor symptoms. The current treatment available does not prevent the progression of the disease and, therefore, new alternatives have been sought for its prevention. Phenolic compounds that are present in foods and beverages of plant origin have bioactivities including antioxidant and anti-inflammatory activity that may contribute to neuroprotection. The general objective of this thesis is to evaluate bibliometric parameters and experimental designs of the 100 most cited articles from WoS-CC on the use of phenolic compounds in Parkinson's disease and to carry out an in vivo laboratory study using Wistar rats exposed to açaí for 15 days before induction of Parkinson's disease-like symptoms through 6-hydroxydopamine. The 100 most cited articles in WoS-CC are predominantly from the Asian continent and China, EGCG and oxidative stress being the most evaluated compound and therapeutic target among the 100 studies. In vitro and in vivo laboratory studies represent approximately 70% of the list. The results demonstrated among the 100 articles are due to concentrations and administration routes that do not resemble consumption through the diet. Pre-treatment with açaí increased GSH levels and decreased MDA levels, in addition to preventing damage to spontaneous locomotion. The results suggest the neuroprotective potential of açaí related to its composition of phenolic compounds.Item Acesso aberto (Open Access) Caracterização molecular in silico de uma mono-oxigenase lítica de polissacarídeo cianobacteriana(Universidade Federal do Pará, 2024-03) VIRGOLINO, Rodrigo Rodrigues; GONÇALVES, Evonnildo Costa; http://lattes.cnpq.br/8652560763793265; https://orcid.org/0000-0003-2221-1995 País de Nacionalidade BrasilLytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that catalyze the oxidative cleavage of β(1-4) glycosidic bonds and have attracted great attention due to importance in increasing the efficiency in degradation of recalcitrant polymeric substrates, in synergism with the action of hydrolytic enzymes, as an accessory function. However, LPMOs act via oxidative cleavage rather than hydrolysis. In industrial applications, LPMOs of fungal origin are the most frequent, while other taxonomic groups have been described as possible alternative sources of these enzymes. In the present study, we aimed to identify and characterize in silico a LPMO of cyanobacterial origin with putative functions in chitin depolymerization. The search for sequence similarity and conservation of domains with other characterized LPMOs identified a 289 AA protein from the cyanobacterium Mastigocoleus testarum of the Nostocales Order, being a probable LPMO of the CAZy-AA10 class. This protein is referred to as MtLPMO10. Phylogenetic analysis revealed that MtLPMO10 is homologous to the Tma12 protein from the fern Tectaria macrodonta, with 52.11% identity, which was the first LPMO characterized as originating from the plant kingdom. The occurrence of shared structural and functional patterns with other AA10 class LPMOs, as well as the existence of variations in these established patterns, contributed to the understanding of the biological functions of this class of enzymes. The predicted protein tertiary arrangement by the AlphaFold server pointed out structural features common to LPMOs, especially a histidine brace composed of His31 and His132 and an immunoglobulin-like domain consisting of antiparallel beta strands. Molecular dynamics simulation (MD) allowed evaluating the enzyme-substrate affinity, using an initial pose based on data obtained from the literature. There was stability of the MtLPMO10-chitoheptaose complex during 100ns of MD, while the MtLPMO10-celloheptaose complex broke apart in 30ns of MD. Also, there was a shorter Cu(I)-H4 distance in the first complex compared to the Cu(I)-H1 distance (averages 6.0 ± 0.7 Å and 7.9 ± 0.7 Å, respectively), suggesting a C4-type regioselectivity, as defined for Tma12. This study highlights the existence of lytic polysaccharide monooxygenases in cyanobacteria and paves the way for further investigations related to this enigmatic class of enzymes and their potential use in biotechnological applications.Item Acesso aberto (Open Access) Biodiversidade bacteriana durante a fermentação espontânea de frutos de açaí (Euterpe oleracea)(Universidade Federal do Pará, 2015-06-22) MOURA, Fábio Gomes; ROGEZ, Hervé Louis Ghislain; http://lattes.cnpq.br/5202118426597590Açai (Euterpe oleracea) fruits (AF) and a wide variety of products derived from this fruit are an example of success of a local and typically Brazilian product on the global market. The AF suffer spontaneous fermentation during postharvest due mainly to its high microbial load and the favourable intrinsic and extrinsic parameters. The biodiversity of microbial community in AF and their evolution between three geographical origins and two fermentation conditions were examined. Culture-independent methods based on 16S rRNA from fifteen samples revealed that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria were the most abundant phyla. At genus level, were identified Massilia (taxon with more than 50 % of sequences remaining constant during the 30 h of fermentation), Pantoea (taxon with the highest increase during fermentation), Naxibacter, Enterobacter, Raoultella and Klebsiella, forming the carposphere bacterial microbiota of AF. Attributes related to plant growth promotion (siderophores) and others compounds e.g. poly-3-hydroxybutyrate (PHB) and violacein in response to stress conditions could improve the Massilia preponderance. Beta diversity showed that quality parameters of AF (pH, soluble solids, titratable acididy and lipids) and elemental analysis (C, N, H and C/N ratio) were unable to establish microbial patterns in AF. This research offers new insights and perspectives of the indigenous bacterial community composition on AF as a function of spontaneous fermentation during postharvest.Item Acesso aberto (Open Access) Avaliação do potencial biotecnológico de compostos isolados de Swietenia macrophylla no tratamento de câncer(Universidade Federal do Pará, 2015-11-30) BARRETO, Leilane de Holanda; MONTENEGRO, Raquel Carvalho; http://lattes.cnpq.br/0043828437326839Swietenia macrophylla (mahogany) is a species of plant widely known for its therapeutic potential. The main constituents isolated extracts of this plant are structures known as limonoids. The limonoids also have several biological activities, among them, antitumor activity. The aim of this study was to evaluate the antitumor potential of the extract and limonoid obtained from leaves of S. macrophylla in cancer cell lines. Cytotoxicity to 5 cancer cell lines and normal revealed that the extract had cytotoxic effect in colorectal cancer cell lines (HCT-116 and HT-29), as the limonoids were cytotoxic for colorectal cancer (HCT-116) and melanoma (SKMEL-19). Given these results, we selected the limonoid L3 and HCT-116 cell line to evaluate the mechanism of action, as well as the HT-29 lineage, which has the TP53 gene mutated for comparison as possible of the compound mechanism of action, once it was less sensitive to L3. Moreover, L3 showed more selective for tumor cells. None of the compounds caused hemolysis of erythrocytes in mice. To evaluate the antiproliferative action of L3, the clonogenic assay was performed, where the two lines there was a significant reduction of colonies, however this reduction was more significant in HCT-116. The L3 compound also has caused death by apoptosis in a dose-dependent manner in the lines, where the number of cells in apoptosis was higher in HCT-116. To evaluate DNA damage, it was held the comet assay, which showed that L3 cause damage to the DNA of the two cancer cell lines, with greater damage index in HCT-116. The assessment of cell cycle distribution of cells after treatment with L3 showed that there was blocking the cycle at the G2 / M phase, mainly in HCT-116 (45% of the cells). From these data, it conducted a study of genes involved in this phase of the cycle, from analysis of their expression by RT-PCR. The ATM gene, which is activated by DNA damage activates the CHK-2 which in turn phosphorylates p53 protein. p53 protein can activate the transcription of p21 gene, which triggers cell cycle stopped, or activate cell death pathways. In this study, we found increased expression of genes ATM, CHK-2, TP53, ARF in a dose dependent in both cacer cell lines, and this expression was higher in HCT-116 cell line. The expression of p21 was increased in HCT-116, while in HT-29 decreased, this is due to the fact that HT-29 possess the mutant TP53 gene, then your protein does not work properly. As the path of apoptosis was evaluated caspase-3 gene and the anti-apoptotic gene BCL-2. There was increase in the expression of caspase-3 mainly in HCT-116 and decrease of BCL-2. These results suggest that L3 may be causing damage to the DNA of cells, triggering a cellular signaling pathway dependent on p53. To evaluate the toxicity of S. macrophylla extract, it was held the acute toxicology testing in mice, where the extract did not cause any changes in the physiological parameters of animals. As the claustogenicidade test (micronucleus) also showed that the extract is not mutagenic in the mouse bone marrow cells.Item Acesso aberto (Open Access) Correlação metabólica entre fungos endofíticos de amaryllidaceae e as plantas hospedeiras na busca por substâncias bioativas(Universidade Federal do Pará, 2016-06-30) SILVA, Suelen Mata da; SANTOS, Alberdan Silva; http://lattes.cnpq.br/5976702134131016The endophytic fungi are a promising source of secondary metabolites with biotechnological applications. These microorganisms inhabit the interior of plant tissues without causing any damage to the host and as a result of this interaction can produce some of the substances synthesized by the host plant. In this context the use of endophytic fungi as a source of biomolecules in the replacement of plant represents economic and environmental advantages. Species in the Amaryllidaceae family produce alkaloids and other metabolites with biological activities. Among these species include Crinum americanum L. and Hymenocallis littoralis (Jacq.) Salisb. However, no data on endophytic fungi from species of the family were found. In the view of the above stated the aim of this work was to scrutinize the biotechnological potential of endophytes of C. americanum and H. littoralis as compared to host plants and to study the interactions between endophytes and host plant. As results 94 endophytic fungi were isolated from two species of the investigated Amaryllidaceae, of which 49 were identified and belonging to the Colettotrichum class, Acremonium, Trichoderma and Fusarium. It was noted that of the total strains tested 56 showed lipids in its extracts, 21coumarins, 29 anthrones and 2 showed alkaloids. 12 strains of endophytic fungi were selected which presented the best results in the detection of classes of metabolites and the extracts were analyzed by Thin-layer chromatography and by Gas chromatography-mass spectrometry in comparison with the methanolic extracts of host plants. It was noted the correlation between the classes of metabolites detected in extracts of the endophytic fungi and host plants, indicating that these micro-organisms are able to produce some of the same substances that the host plants and the assessment of antimicrobial activity highlighted some extracts with activity against Candida parapsilosis. The methanolic extract of leaves of H. littoralis and endophytic fungus MIBA 0796 presented the most relevant outcomes with percentage of inhibition above 60% against yeast. With the study of the interaction between C. americanum endophytes and the host plant it can observe that microorganisms act within the plant cells and in favorable conditions develop and occupy intercellular spaces as well. This location of the Endophytes in plant tissues may facilitate the exchange of genetic material between plants and microorganisms explaining how metabolic correlation found in this research.Item Acesso aberto (Open Access) Vitrificação de tecido ovariano de gata doméstica (Felis catus): um modelo para a preservação da fertilidade em felinos silvestres(Universidade Federal do Pará, 2016-09-06) BRITO, Danielle Cristina Calado de; SANTOS, Regiane Rodrigues dos; http://lattes.cnpq.br/0500967766886604; PIECZARKA, Julio Cesar; http://lattes.cnpq.br/6644368250823351The aim o the present thesis was to develop an efficient vitrification protocol of the ovarian tissue from domestic cat (Felis catus). This study was divided: Phase I: Effect of different basis media during the vitrification of cat ovarian tissue; Phase II: Effect of different sugars (extracellular cryoprotectants) and the vitrification technique for the vitrification of feline ovarian tissue. In phase I, the morphology of preantral follicles was similar (p > 0.05) to fresh control when RPMI-1640 was used as basis medium for vitrification. RPMI-1640 does not contain phenol red, which was found to enhance ethylene glycol (EG) toxicity during vitrification. In phase 2, the percentage of morphologically normal preantral follicles was similar (p > 0.05) to fresh control only when the vitrification medium contained 0.1 or 0.5 M trehalose, instead of sucrose or raffinose at same concentrations. Furthermore, based on parameters such as morphology, cell proliferation and thickness of collagen fibers, it is possibe to assume that efficient vitrification of feline ovarian tissue can be performed by combining trehalose with EG, with or without dimethylsulfoxide (DMSO), applying the solid-surface vitrification (SSV) or ovarian tissue cryosystem (OTC) method. Although vitrification with OTC in the presence of EG did not differ from the other treatments, this protocol presented the highest percentages of preserved preantral follicles (56%), being similar to control (64%). Additionally, no effect on gene regulation was observed after vitrification when apoptosis markers (BAX – protein X associated to Bcl-2), endoplasmic reticulum (ER) stress (ER protein 29 – ERP29), water channels proteins like aquaporins 3 and 9 (AQP3 and AQP9), the membrane ABC transporters ABCB1 and ABCG2, except when the SSV method was applied using only EG as cryoprotectant followed by seven days in vitro culture, where ERP29 up-regulation (ER stress) and AQP9 down-regulation (impaired water transport) were observed. Based on this, it can be concluded that to efficiently preserve feline ovarian tissue, is is necessary the use of a vitrification protocol free of phenol red, supplemented with trehalose, as extracellular cryoprotectant, and EG alone or in combination with DMSO, as intracellular cryoprotectants. Both open (SSV) and closed (OTC) systems are equaly efficient to maintain follicular survival during the vitrification procedure.